Modern vehicles typically have one or more diagnostic systems, generally having separate computer control modules to control various functions of the vehicle. Some examples include powertrain control module (PCM), engine control module (ECM), a transmission control module (TCM), anti-locking brake system (ABS) module, and an air bag control module. The vehicle diagnostic systems often have self-diagnostic capability to detect and alert the driver of problems the vehicle may be encountering. When a problem is found, a diagnostic trouble code or DTC, is set within the computer's memory. DTCs are as general or as specific as the manufacturer desires.
To retrieve and decipher DTCs, an auto repair technician needs a diagnostic tool, such as a scan tool. The scan tool must, therefore, be connected to the vehicle's computer bus system to access and retrieve the DTCs. Scan tools are testing devices that interface with vehicle diagnostic systems to retrieve information from the various control modules. The scan tools are equipped to communicate in various communication protocols such as Controller Area Network (CAN), J1850 VPM and PWM, ISO 9141, Keyword 2000 and others. These communications protocols may be specific to the various automobile manufacturers. The scan tool will help the technician to diagnose and repair the vehicle based on the information the tool retrieves from it.
The amount of information that can be stored on a scan tool is tied to the amount of memory the scan tool has. Scan tools are currently programmed at the factory with all the necessary information for all vehicles for a desired cover range, such as from 1996-2000. The desired range may be more than what the technician needs and thus the additional memory in the scan tool is wasted with unnecessary information. Memory is one of the costly components of the scan tool, thereby excessive memory makes the scan tool cost more than necessary.
Therefore, it is desirable to provide a method that allows a technician to configure the scan tool to contain only the desired information specific to the vehicle or vehicles that he is working on.